OBJECTIVE: The impact on health economic outcomes of using either Framingham or United Kingdom Prospective Diabetes Study (UKPDS) risk equations for stroke and myocardial infarction (MI) was evaluated. The effects of interventions aimed at lipid profile improvement, blood pressure control, or improved glycemic control were modeled in typical type 2 diabetes cohorts using either the Framingham or the UKPDS risk formulae embedded in a documented, validated type-2 diabetes simulation model. METHODS: The progression of diabetes complications including both micro- and macrovascular disease was simulated. Total lifetime costs/patient (TC), life expectancy (LE), and costs/life-year gained (C/LYG) of 3 hypothetical interventions affecting either lipid profile (LDL lowered from 150-120 mg/dl and HDL raised from 35 to 45 mg/dl costing $300/year/patient), blood pressure (systolic blood pressure reduced from 170 to 140 mmHg costing $300/year), or glycemic control (HbA1c lowered from 10 to 8.5 %, costing $300/year) were calculated. RESULTS: Using Framingham formulae consistently underestimated improvements in LE when compared to using UKPDS formulae. Due to the interplay of a number of factors, effects on TC and C/LYG were less consistent. In the lipid-intervention, LE improved by 0.41 years using Framingham formulae, and by 0.74 years using UKPDS. TC were increased by ~ $3,400/patient using both sets of formulae, but C/LYG were $13,094 using Framingham and $7,103 using UKPDS. In the blood pressure intervention, LE improved 0.40 or 0.52 years using Framingham formulae or UKPDS respectively. TC were decreased by around $5,814/patient using Framingham, and by $6,591 using UKPDS. In the glycemic control intervention, LE improve 0.37 years using Framingham formulae, and by 0.66 years using UKPDS. TC were decreased by $20,072/patient and by $4,948 using Framingham or UKPDS respectively, but C/LYG were $13,094 using Framingham and $7,103 using UKPDS. CONCLUSIONS: The choice of cardiovascular disease risk formulae has an important impact on long term health economic outcomes of type-2 diabetes patients, and the predicted cost effectiveness of interventions.